Therefore, similar to models [1]}, [2]}, we define \(Q\)  as the set of pixels on the object boundary the object and \(\text{IS}_i\)  the set of pixels belonging to instance mask \(i\) .
For every pixel \(p\) , we compute a truncated distance \(D_t(p)\)  to \(Q\)  as,
\( D_t(p) = \gamma _p \min \big ( \min \lceil d(p,q) \rceil , R \big ), \quad \forall \,q \in Q\) 
